TL;DR: The standard pigmentation protocol was developed on Fitzpatrick II-III skin and routinely fails on V-VI. The active that works for a Korean reader with PIH from acne is not the same active that works for a Nigerian reader with melasma. Davis and Callender mapped the divergence in 2010. I have watched the wrong recommendation produce rebound pigmentation in three friends. The pyramid is not the same shape across skin tones.
A reader in Lagos sent me before-and-after photos in March of a six-month course on hydroquinone 4% that her dermatologist had prescribed for melasma across her cheekbones. The first three months had been excellent. Months four through six were a slow disaster. The original pigmentation was lighter but the surrounding skin had developed a faint exogenous ochronosis pattern and there was new rebound pigmentation at the borders. She asked me what had gone wrong. The honest answer is that the duration was wrong for her Fitzpatrick type. The protocol that produces consistent results on a IV skin can produce ochronosis on a VI skin. The standard advice does not account for this.
The pigmentation literature has a problem. Most of the foundational studies, particularly the ones from the 1980s and 1990s that established the tyrosinase-inhibition framework, were conducted on Fitzpatrick II and III subjects. The protocols that emerged work reasonably well in that range. They translate badly to V and VI, where the melanocyte density is similar but the melanosome size, distribution, and transfer dynamics are different. Davis and Callender catalogued this discrepancy in 2010 and the field has been slowly correcting course since.
What the studies actually show
Davis and Callender 2010 (PMID: 20725554) reviewed PIH treatment outcomes specifically in skin of colour, defined for the paper as Fitzpatrick IV through VI. The team documented the recurrence rate, the time to clinical clearance, and the most common iatrogenic complications. The headline finding is that aggressive treatment protocols, including high-strength tretinoin combinations and prolonged hydroquinone courses, produce more rebound pigmentation in darker skin than in lighter skin. The melanocyte in V-VI skin appears to be more reactive to inflammatory triggers, including the inflammatory triggers produced by the treatment itself.
The implication is consequential. In Fitzpatrick II-III, the standard PIH protocol of tretinoin 0.05% plus hydroquinone 4% for twelve to sixteen weeks produces good outcomes with low recurrence. In Fitzpatrick V-VI, the same protocol produces clearance, then a fresh wave of PIH around the original lesion site, often within three to six weeks of stopping the treatment. The skin clears and then re-darkens, sometimes in a slightly different pattern from the original.
Sarkar et al. 2014 (PMID: 25396122) and the 2018 update (PMID: 29984699) catalogued the melasma treatment hierarchy with explicit attention to skin tone. The team found that triple combination therapy, the Kligman formula of hydroquinone, tretinoin, and a mid-potency corticosteroid, produces faster clearance in IV and V skin but requires more careful taper-down to avoid rebound. The optimal duration is shorter than the duration that maximises initial clearance. The clinician has to stop while the skin is still slightly hyperpigmented to avoid the rebound.
Callender et al. 2011 (PMID: 21348540) is the etiological companion paper. The team described the cellular dynamics of post-inflammatory hyperpigmentation across skin tones. In V-VI skin, the inflammation that triggers PIH does not need to be severe. A mild irritant contact dermatitis from a fragrance or a low-grade folliculitis can produce months of residual pigmentation. The threshold for inflammation-triggered melanogenesis appears lower as Fitzpatrick number rises.
The pyramid as it is usually drawn
The conventional hyperpigmentation pyramid lists actives in roughly this order of strength. At the top, hydroquinone 4% prescription, often in combination with tretinoin and a corticosteroid. Below that, tretinoin monotherapy at 0.025% to 0.1%. Then azelaic acid 15-20%. Then alpha arbutin, kojic acid, and niacinamide at the over-the-counter tier. At the base, antioxidants like vitamin C and tranexamic acid topicals.
This pyramid is approximately right for Fitzpatrick II-III. It is the wrong shape for V-VI. The Davis-Callender data and the Grimes 2009 (PMID: 19608058) review both argue for a flatter pyramid with different ingredient priorities for darker skin.
The pyramid for Fitzpatrick V-VI
For very dark skin, the priorities reorder. The risks of aggressive treatment exceed the benefits of faster clearance in most cases. The Grimes paper makes the explicit point that “less is more” describes the V-VI protocol better than the standard PIH literature suggests.
Tier 1, the actives that do most of the work without producing rebound, are azelaic acid 15-20%, tranexamic acid topical, and niacinamide 4-5%. These three are sometimes dismissed as “weak” in V-VI contexts. They are not weak. They are appropriate. Azelaic acid in particular inhibits tyrosinase selectively in hyperactive melanocytes, leaving normal pigmentation undisturbed. The Skinoren formulation at 20% and The Ordinary Azelaic Acid Suspension 10% are both reasonable starting points. Sarkar’s 2014 review identifies azelaic acid as a first-line option specifically because of its safety profile in darker skin.
Tier 2 adds cysteamine 5%, alpha arbutin, and low-strength retinoids like adapalene 0.1% or tretinoin 0.025%. The retinoid is the variable that requires the most caution. The same molecule that fades pigmentation in II-III can trigger fresh PIH in V-VI if the irritation threshold is exceeded. A retinoid in V-VI skin should be introduced at the lowest concentration, applied every third night for the first month, and combined with a barrier-supporting moisturizer.
Tier 3, used cautiously and for limited durations, includes hydroquinone 2-4%. The recommended cycle in V-VI is no more than twelve consecutive weeks followed by a mandatory three-month off period. This is more conservative than the II-III protocol. Exogenous ochronosis, the bluish-grey deposition that occurs with prolonged hydroquinone use, is documented overwhelmingly in V-VI skin and rarely in lighter tones.
Tier 4, for refractory melasma in skilled hands, includes oral tranexamic acid and laser interventions. Laser in V-VI requires specific wavelengths and pulse durations to avoid the depigmentation and rebound risks that plague pigment-targeted lasers in darker skin. The Q-switched Nd:YAG at low fluence is the workhorse. The picosecond lasers have a growing but uneven evidence base in this population. Anything in this tier requires a clinician with specific experience in skin of colour. The cost of a wrong laser setting on Fitzpatrick VI skin is months of new PIH.
The pyramid for Fitzpatrick III-IV
The intermediate tones sit closer to the standard literature but have their own considerations. Sarkar’s group has published extensively on melasma in South Asian populations, where Fitzpatrick III-IV predominates. The protocols that work here include tretinoin 0.05% combined with hydroquinone 4% in shorter cycles, azelaic acid 15-20% as a maintenance phase, and aggressive sun protection.
The sun protection variable is enormous in this group. Melasma in III-IV skin is dominantly UV-driven and visible-light-driven. The pigmentation responds to sunscreen as much as to active treatments. Iron oxide-containing tinted sunscreens, which block visible light, are more effective than transparent sunscreens for melasma management in this group. La Roche-Posay Anthelios Mineral One and Beauty of Joseon Relief Sun with iron oxides are both reasonable choices.
Tranexamic acid topical at 3-5% is a useful adjunct in III-IV melasma. The Sarkar 2018 update describes the evidence base. The molecule reduces melanogenesis through a different pathway than tyrosinase inhibition and stacks usefully with other actives.
What the wrong recommendation looks like
A friend in Atlanta with Fitzpatrick V skin used 4% hydroquinone for nine months continuously on her cheekbones for melasma in 2019. The initial clearance was excellent. The exogenous ochronosis that developed in month seven took two years to fade. Her dermatologist had not stopped the treatment at twelve weeks because the patient had wanted continued clearance and the clinical guidelines on duration in darker skin had not been part of the original conversation.
A second friend in Toronto with Fitzpatrick VI skin used tretinoin 0.05% nightly for PIH from a folliculitis episode. The PIH cleared. New PIH developed in a halo around the original site within six weeks of the tretinoin starting, because the retinoid irritation produced the same low-grade inflammation that the folliculitis had. The protocol that would have worked was tretinoin 0.025% every third night with a ceramide moisturizer underneath. The lower concentration and the spacing matter.
What I would tell my past self
If your skin is Fitzpatrick V or VI, do not start with the strongest active you can find. The pyramid is inverted for you. Azelaic acid first. Months of azelaic acid, not weeks. Niacinamide stacked. Sunscreen daily, with iron oxides if you can find a formulation that works on your skin tone (the Beauty of Joseon Relief Sun has a slight white cast that resolves on V skin; on VI skin the EltaMD UV Daily Tinted is a closer match).
If you escalate to hydroquinone, set a calendar reminder for week ten. Stop at week twelve no matter what the skin looks like. Take three months off. If you continue past twelve weeks because the result is incomplete, the rebound and ochronosis risks compound steeply.
If you are using a retinoid for pigmentation in darker skin, start with adapalene 0.1% before tretinoin. The irritation profile is gentler and the PIH risk is lower. The pigmentation effect is similar over six to nine months.
Find a dermatologist who has explicit experience with skin of colour. The protocols are different and a clinician trained primarily on II-III patients will sometimes default to the wrong pyramid. Callender, Grimes, Sarkar, and Taylor have all published extensively on skin of colour and the clinicians who cite them in their teaching are usually a safer bet.
The pigmentation you have today did not appear overnight. The treatment that fades it without causing new pigmentation will not work overnight either. Twelve months is a reasonable horizon for visible improvement on stubborn PIH or melasma in V-VI skin. The brands that promise four-week clearance are selling a problem, not a solution.
FAQ
Why does hydroquinone cause more problems in darker skin?
The melanocytes in V-VI skin are more reactive to inflammatory and chemical triggers. Prolonged hydroquinone exposure can produce paradoxical pigmentation (ochronosis) at higher rates in this group. The risk is duration-dependent, which is why the maximum continuous use guidance is shorter than for lighter skin.
Is tretinoin safe for hyperpigmentation in V-VI skin?
Yes, at low concentrations and with careful introduction. Tretinoin 0.025% every third night with a ceramide moisturizer underneath is a reasonable starting protocol. Adapalene 0.1% is often a gentler entry point. The irritation that triggers PIH in this skin tone is the variable to manage.
Does iron oxide sunscreen actually matter for melasma?
Yes for III-IV melasma in particular. Visible light contributes meaningfully to melasma pathogenesis in pigmented skin. Iron oxide pigments block visible light in a way that mineral and chemical UV filters do not. Tinted formulations are more effective than transparent ones for melasma management.
How long until I see results on azelaic acid for PIH?
Eight to sixteen weeks for visible improvement. The Sarkar and Davis-Callender reviews both describe azelaic acid as a slow-onset agent. The advantage is the safety profile. The disadvantage is the patience required.
Can I use vitamin C with hydroquinone?
Yes. The two work through different mechanisms and stack usefully. Vitamin C contributes antioxidant photoprotection and modest tyrosinase inhibition. The combination is sometimes used as a maintenance phase after hydroquinone is discontinued.
Related Elelaf tools
Sources
- Davis EC, Callender VD. Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. J Clin Aesthet Dermatol. 2010;3(7):20-31. PMID: 20725554
- Sarkar R, Arora P, Garg VK, Sonthalia S, Gokhale N. Melasma update. Indian Dermatol Online J. 2014;5(4):426-435. PMID: 25396122
- Sarkar R, Bansal A, Ailawadi P. Future therapies in melasma: what lies ahead? Indian J Dermatol Venereol Leprol. 2018;84(5):529-540. PMID: 29984699
- Callender VD, St Surin-Lord S, Davis EC, Maclin M. Postinflammatory hyperpigmentation: etiologic and therapeutic considerations. Am J Clin Dermatol. 2011;12(2):87-99. PMID: 21348540
- Grimes PE. Management of hyperpigmentation in darker racial ethnic groups. Semin Cutan Med Surg. 2009;28(2):77-85. PMID: 19608058